Needle bar for hosiery linking machines



United States Patent Cesare L. Conti Via Varese 18, Milan, Italy [21] Application No.: 734,982

[72] Inventor:

[22] Filed: June 6, 1968 [45] Patented: Aug. 4, 1970 [3 2] Priorities: June 28, 1967 3 3 Italy April 12, 1968, Italy,

[54] NEEDLE BAR FOR IIOSIERY LINKING MACHINES 4 Claims, Drawing Figs.

Primary Examiner Mervin Stein Assistant E,\'aminer Geo. V. Larkin Attorney B. Edward Shlesinger ABSTRACT: A needle-bar for linking machines (loopers) for hosiery is disclosed, in which the needle is mounted eccentrically with respect to the axis of said needle-bar. Means are further provided for varying the eccentricity of the needle with respect to the needle-bar, care being taken in any case that the axes of the needle and the needle-bar are rigorously parallel to one another. The advantage afforded by the novel eccentric needle bar is that, whenever the needle bar is to receive, in addition to its conventional reciprocal motion, also a partial alternating rotation about its own axis, the control mechanisms which govern the movement of the needle bar can be considerably simplified. Thus, the reliability of the machine and its working speed are considerably improved.

Patented Aug. 4, 1970 3,522,780

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BY ATTORNEY Patented Aug. 4, 1910 3,522,780

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jZQ T T ORNEY U.S. PATENT 3,522,780 NEEDLE FOR IIOSIERY LINKING MACHINES FIELD OF THE INVENTION This invention relates to a constructional arrangement of needle bars, especially for hosiery linking machines.

BRIEF SURVEY OF THE PRIOR ART It is known long since that linking machines in general possess, as one of their essential members for formation of the kind of stitch selected according to the work to be completed, a needle bar intended for firmly supporting the needle and imparting thereto any desired movement by the agency of appropriate mechanisms: these latter will no longer be cited in detail since they are well known to those skilled in the art and, on the other hand, they do not form an integral part of the subject invention.

It is likewise knownthat linking machines of a particular kind are in use, wherein the needle bar not only receives the conventional movements, but is to perform a more complex movement, that is, a movement of alternating partial rotation about its own axis. An example of a needle bar which receives such an alternating angularly limited axial rotation movement is the machine disclosed and claimed in the copending U.S. Patent Application Serial No. 610,948 filed January 23, 1967 by the same Applicant, now patent No. 3,476,064.

Briefly summarizing the foregoing, the principal object of this invention is to simplify to the utmost the control mechanisms in all the cases in which the needle bar of a linking machine is to receive, in addition to its usual rectilinear reciprocation, a movement perpendicular thereto for achieving the cooperation between the needle bar and the impaling pins for the work: the latter movement is conventionally performed at present by means of a cam and appropriate crank mechanisms: these latter can now be dispensed with in an advantageous manner by resorting to the teachings of the present invention, the result being a considerable simplification of the construction of the machine, which also entails a remarkable increase of the speed of operation thereof.

BRIEF SUMMARY OF THE INVENTION Broadly, according to the present invention, the needle is eccentrically mounted with respect to the needle bar, means being preferably, but not necessarily, provided for varying, either upon assembly or during the operation of the machine, said eccentricity within a certain range, the needle bar further receiving a movement of partial alternating rotation about its own axis.

It can easily be understood, at this stage, that the invention can be put into practice by extremely simple and cheap means.

The means provided for varying the eccentricity of the needle with respect to the needle bar are many; thus, an infinity of these means can be envisaged without departing from the spirit and scope of this invention; what actually matters is that such an eccentricity exists and, preferably, that it be adjustable. In certain cases, the needle-bar and needle assembly can be provided beforehand with a fixed eccentricity, said fixed eccentricity being selected to fulfil certain particular require ments, for example for the production of a certain class of hosiery articles.

The means provided for imparting to the needle bar the above cited alternating partial rotary movement about its own axis are also many: by way of example, see the linking machine disclosed and claimed in U.S. Patent Application Serial No. 610,948 cited hereinabove.

DETAILED DESCRIPTION OF THE INVENTION 7 The invention will now be illustrated and described in connection with an exemplary embodiment thereof, it being understood that any other mechanical means capable of varying the eccentricity of the needle with respect to the longitudinal center line of the needle bar within a preselected range (in practice a few millimeters or even a fraction of a millimeter in certain cases), in conjunction with any other means adapted to impart to the needle bar a movement of partial alternating rotation (ilc. angular oscillation) about its axis, embodies the present invention.

In addition, a practical example will be given of a manner in which the present invention can be applied to a hosiery linking machine.

The above cited exemplary embodiment and practical application of the invention are shown in detail in the accompanying drawings, wherein:

FIGURE I is a side elevational view of a needle bar having an eccentric needle according to this invention.

FIGURE 2 is a plan view of the needle bar shown in FIG. 1.

FIGURE 3 is a diagrammatical showing of the horizontal reciprocation of the needle bar and its angular swinging motion on a vertical plane which is perpendicular to the axis of the needle bar.

FIGURE 3a is a perspective view of a stitch-formation mechanism which utilized an eccentric-needle needle-bar according to this invention.

FIGURE 4 is a perspective view of a mechanical unit which imparts an elliptical or oval movement to a thread-guide of a hosiery linking machine.

The arrangement shown in FIGURE 1 discloses a needle bar, 1, mounted in a clamp 3. Said clamp can be tightened with a threaded-pin tightening device having a threaded pin 4, whereas a small cylinder 2 acts as an abutment for the front end (as viewed in FIG. 1) of the needle bar 1. A needle, 6, is'

integrally mounted in a needle-carrying block 5 (the needle being held in fixed position, for example, by a screw which has not been shown to simplify the drawing), and said needle-carrying block is firmly fastened to the clamp 3.

It is apparent that, by shifting the assembly comprising the clamp 3, the block 2 and the needle bar 1, the eccentricity, h, that is the distance between the axis of the needle 6 and the axis of the needle-bar 1 can also be varied. The same arrangement of component parts can be seen, in plan view, in FIG. 2: in this drawing, the eccentricity, h, cannot be seen any more, since it has been assumed, in this case, that said eccentricity is referred to a vertical plane containing both the axes of the needle and the needle-bar when these two members are in their starting or inactive position. Said geometrical assumption has been made for simplification only. Otherwise, what has been said in connection with FIG. 1 holds good also for FIG. 2.

It should be noticed, also, that the exemplary embodiment depicted in FIGS. 1 and 2 of the accompanying drawings is not to be construed as a limitation of the scope of the invention: as a matter of fact, the mechanical means adapted to vary the eccentricity of the needle with respect to the needle-bar can be selected among a wide variety: for example, instead of the combination clamp-blockmeedle bar, a needle-carrier can be provided, which is mounted on a small slide adapted to glide on ways integral with the front end of the needle bar, while a set screw, properly located, could serve to lock the whole assembly in the position which corresponds to the preselected eccentricity.

What actually matters, in practice, is that the eccentricity and the angle of partial alternating rotation, alpha (FIG. 3) in combination, correspond to those values which allow the needle to stay in registry with the working pin.

FIGURE 3 clearly shows the movements imparted to the needle. More accurately, the line la, the reference numeral being the same adopted for the longitudinal center line of the needle bar 1, denotes the reciprocal movement of the needle, whereas thesector having the center angle alpha defines an arc AB which is the arcuate path on which the needle point travels during a partial alternating half-rotation, said path corresponding to one half of the inter-pin gap or machine gauge.

The center angle alpha is generally in the order of magnitude of said value being, however, given by way of suggestion only.

To show the advantages of the invention in a simple manner, it will be enough to say that the conventional needlesynchronizing mechanism with return spring, which is commonly adopted to effect the movement of vertical oscillation of the needle can be totally dispensed with if the inventive.

device is adopted: in addition to that, the possibility is affordcd of effecting an adjustment which could not be obtained with the prior art arrangements.

A PRACTICAL EXAMPLE OF APPLICATION OF THE INVENTION Referring now to the example shown in FIGS. 3a and 4 hereof, a practical application of the inventive device to a linking machine in which the needle is mounted externally to the pin dial, will be described. In order that overcrowding of the drawings may be avoided and also that parts unnecessary to the understanding of the invention may be shown, only the end portion of the arm of the linking machine has been shown: the dial has been shown only diagrammatically, but in a manner which is largely sufficient to give a clear understanding of the invention.

The head 101 of the linking machine arm carries the stitchforming mechanism. Said device comprises a needle, 102, eecentrically mounted on its needle-bar, 103. It will be observed that the longitudinal center lines of the needle and of the needle-bar, respectively, are not coincident, but they must be rigorously parallel to one another, otherwise the loop-stitch forming movement would be wholly irregular. The needle bar 103 is both slidably and rotatably supported within a supporting member 104 which, as shown in the drawing, can be, for example, a mere extension of the head 101. At the left end, as viewed in FIG. 3a of the needle bar 103, is mounted a crank 105 which imparts the rotary movement of the needle bar 103 about its axis. The crank 105 carries, perpendicularly thereto, an end pin 106 having a spherical extension which is shown in phantom lines in FIG 3a. As shown in the drawing, the pin 106 is mounted on the free end of the crank 105. The spherical end of the pin 106 slides within a longitudinal vertical groove 7 formed in a small block 8. The block 8 is mounted at the end of a lever 9. The lever 9 is pivotally mounted about an intermediate point by means ofa through-pin 10 (not shown in the drawing, which only indicates the axis of said pin), and the pin 10 is downwardly extended until it is received by a block 11. At the top, the through-pin 10 is received by a second block 11, which is reciprocable along a cylindrical guide 12. Said cylindrical guide 12 is affixed, at its ends, to the head 101, as shown in the drawings. At its end away from the end which carries the grooved block 8, the lever 9 is connected to one end of a crank 13. The other end of the crank 13 is integral with an arbor 14, which receives a continuous rotary drive from conventional drive-transfer members (e.g. bevel gears) actuated by the usual motor of the linking machine.

By examining FIGURE 3a again, the operation of the device will become fully apparent: as a matter of fact, the arbor 14, continually driven by the machine motor, rotates the crank 13 which, in turn, oscillates lever 7. The latter, pivoted at 10, is rotated about its own pin and also receives a reciprocal motion whose stroke is defined by the length of the cylindrical guide 12. This stroke defines the path of reciprocal motion of the needle-bar 103. As a matter of fact, the pin ofthe lever 9 is extended downwardly into block 11. The rotary movement of the needle-bar about its own axis is effected by the grooved block 8, placed at the free end of the lever 9. The mechanical linkage between the needle-bar 3 and the lever 9 is through pin 106, whose spherical extension is perpendicular to crank 105. It can now be easily understood that an oscillation of the lever 9 causes an oscillatory movement of the crank 105 and thus also of the needle bar 103.

The eccentric mounting of the needle on its needle bar eliminates the mechanism and the return spring which have heretofore been required to impart the vertical movement to transfer the needle from one impaling pin to the next one. The advantage achieved thereby is especially conspicuous in linking machines having the needle mounted outside the pin dial. As is known, the needle synchronization mechanism can be mounted, for a linking machine having an internal needle, in the cup-shaped space placed internally of the pin dial, whereas the mounting of such a synchronization mechanism would be extremely cumbersome for a linking machine having the needle external to the pin dial, since, in such a case, a rather intricate and costly linkage should be provided.

Coming now to FIGURE 4 of the accompanying drawings, a device has been shown which is intended to impart to the thread feeding and guiding unit the elliptical movement which is necessary to form the loop stitch in cooperation with the movement of the needle.

Internally of the pin dial, 29, the thread feeding and guiding mechanism is mounted. It comprises, in the order given, and from the right to the left as viewed in FIG. 4, a gear pair 15, 17 by which the drive received from the motor of the machine, is transferred to the gear 17 and, therefrom, to the shaft 16 to which the latter gear is keyed. To the shaft 16 is keyed a gear 18 meshing with the gear 19. The gear 18 has twice the number of teeth of the gear 19, so that the relative gear ratio is 2 to 1. The shaft of the gear 19 (a small portion of it can be seen) is received by a cylindrical supporting member 20 and, at the end of the shaft which rotates in 20, there is an eccentric 21, mounted internally and thus not shown in the drawings. The internal eccentric 21 transfers its drive to the block 22, which carries a cylindrical rod 23. The lower end of the rod 23 cooperates with a balljoint 24 mounted at the end of an arm 25, the latter protruding from a bracket 26. At the upper end of the rod 23 is removably and adjustably mounted an arm 27 which is extended to form the thread-guide proper 28. As viewed in the drawing, by virtue of the rotation of the gears 15, 16, 18, 19 and of the internal eccentric 21, as well of the universal joint arrangement of the rod 23 (as guided by the block 22, it can readily be seen that the tip ofthe thread-guide 28 goes over an oval path whose major axis is nearly horizontal. This movement, in cooperation with the movements of the needle, originates the desired loop stitch.

It should be observed that, on account of the considerable constructional simplification made possible by the invention, which has permitted dispensing with several component parts, a linking machine equipped with the inventive device as now described is capable of attaining extremely high speeds. which are in any case higher than the working speeds obtainable with the conventional hosiery linking machines. The elimination of a few component parts has led not only to the immediate consequence of first-cost reduction, but also to the elimination of undesirable inertia forces and vibrations.

lclaim:

1. In a hosiery linking machine a needle bar mounted for oscillation and for rectilinear reciprocation in the direction of the axis of oscillation of said bar,

a needle mounted on said bar to extend parallel to but be eccentric of the axis of oscillation ofsaid bar, and

means for imparting reciprocation to said bar in the direction of said axis and for simultaneously effecting oscillation of said bar about said axis.

2. In a hosiery linking machine as claimed in claim 1, means for adjusting the eccentricity of said needle relative to said axis.

3. A hosiery linking machine as claimed in claim 2, wherein the means for varying the eccentricity of said needle comprises a block abutting the front end of said needle bar, a clamp for releasably securing said block to said bar, and a block in which said needle is mounted to project forwardly parallel to the axis of said bar, said clamp being releasable to adjust the amount of offset of said needle from the axis of oscillation of said bar.

dle, and the other of which is fixed to said needle bar, and screw means for fastening said two members to one another with the needle in the desired position eccentric of the axis of oscillation of said bar. 

